The present invention may advantageously be applied to a very high rate digital subscriber line (VDSL) environment or system, for example, though the invention may also be used in other applications. That is, the invention applies to a digital communication system linking an operator and users via very high bit rate transmission lines. Thus, the invention applies more particularly to send/receive devices, usually referred to as modems, at the operator and user ends of a transmission line.
Those skilled in the art will appreciate that a VDSL communication system is capable of delivering symmetrical services and asymmetrical services. A service is symmetrical if the bit rate of information exchanged between the operator and the user in both transmission directions (i.e., from the operator to the user and from the user to the operator) is exactly the same. A service is asymmetrical if the bit rate of information sent in one transmission direction is different from the bit rate of information sent in the other transmission direction.
The processes of interleaving and deinterleaving data sent and received by a modem necessitates the use of memories. For a modem intended to operate at a predetermined bit rate, the memories must have a capacity that depends on that bit rate.